This invention pertains to a method for making removable partial dentures. More particularly, the invention relates to a method for making a component part removable partial denture in which the framework is designed, waxed up, and constructed as separate parts, and the separate parts are joined together when positioned on a master cast.
Removable partial dentures and methods for casting frameworks for them have been known to dentists and technicians for many years. The conventionally used technology for constructing removable partial denture frameworks is represented by that of "Ticonium" casting, using primarily preform plastic patterns and a single sprue, as is set forth in the "Ticonium 100 Premium Technique Manual," prepared by the Ticonium Company, Division of CMP Industries, Inc., 413 N. Pearl Street, Albany, New York, 12201. The widely used "Ticonium" casting method for producing removable partial dentures suffers from the disadvantage that because of shrinkage of the metal, abberrations in the form of the casting appear during cooling. The finished product frequently fails to conform to mouth contours of the patient and may require significant adjustment. A removable partial denture cast in the conventional manner may "rock" from one side to the other, or from front to back, or may impinge upon the underlying tissue to the extent that the removable partial denture causes tissue irritation, tissue damage due to excess pressure, enamel abrasion, or increased mobility of abutment teeth.
A primary object of the present invention is to provide a component part removable partial denture which is designed as at least two independent units: a first component which is tooth-supported and a second component which is tissue-borne, for the purpose of providing optimum passive fit of the resulting framework to the supporting teeth simultaneous with optimum fit of the framework to subjacent tissue in the mouth of a patient.
Another object of the present invention is to provide component parts of a partial denture which, after they are produced, can be positioned on a master cast and locked together by mechanical locks cast into the frame components, using a high-impact visible light cured resin to form a single, rigid, functioning unit.
A further object of the present invention is to provide a method for producing a component part removable partial denture which allows for correction of casting distortions by using a visible light cured resin to lock together the components, after the components have been produced and fitted on the master cast.
Another object of the present invention is to provide a method for producing component part removable partial dentures which increases the design and construction possibilities to include designs which cannot consistently normally be produced in a single unit casting such as a removable tooth-supported bridge held in place by interproximal bracing and other framework configurations which more nearly resemble a fixed partial denture, and the use of biocompatible metal bases and major connector component parts.
Yet another object of the present invention is to produce a component part removable partial denture which, because of its precision casting and fit, can be designed to be more cosmetically acceptable to a wearer by providing fewer facial clasps.
Another object of the present invention is to provide a component part removable partial denture which can be easily removed for cleaning, and which accordingly tends to improve the oral hygiene of the patient.
A further object of the present invention is to provide a component part removable partial denture which can be constructed having a decreased amount of tissue coverage for many designs and consequently a lesser likelihood of tissue inflammation.
Another object of the present invention is to provide a component part removable partial denture which fits more precisely in a wearer's mouth, so that less movement and consequently less abrasion and tooth mobility occurs while the removable partial denture is in the patient's mouth.
Yet another object of the present invention is to provide a component part removable partial denture precisely constructed so that there is less patient awareness and greater likelihood of acceptance by patients.
A further object of the present invention is to provide a component part removable partial denture and method for constructing same wherein minor fit problems can be corrected in the patient's mouth, and it is not required to construct a new framework when such fit problems occur.
Another object of the present invention is to provide a component part removable partial denture which is more consistent in quality of fit and correctability, and less expensive to construct than the presently available fixed partial dentures, which it more closely resembles.
These and other objects, features, and advantages of the invention will become apparent to those skilled in the art in the light of the following detailed description, viewed in conjunction with the referenced drawings, of a preferred component part removable partial denture and method for constructing same according to the teachings of the present invention. The foregoing and following description of the invention is for exemplary purposes only. The true spirit and scope of the invention is set forth in the appended claims.